1. add the ppa
sudo sh -c "echo ‘deb http://archive.canonical.com/ubuntu/ trusty partner‘ >> /etc/apt/sources.list.d/canonical_partner.list"
2. update system repository
sudo apt-get update
3. install
sudo apt-get install skype
原文：http://www.cnblogs.com/aqing1987/p/4949140.html